macdan
TiBook display take-apart, re-assembly and
various other related infos
Apple glued the darn thing together, which makes
it a tad difficult to replace broken LCDs and
hinges. My main additions to the existing
literature are my technique for separating the LCD
from its bezel, as well as identifying the glues
and techniques Apple used to stick it all together
in the first place.
As of April 2007 I've also added some info on
hinge replacement, differences between various LVDS
cables, sleep magnet locations and more. The page
is still not as complete as I'd like, but it is
looking a little better.
Hope this info is useful, if you have any
comments, questions or just wish to chat you can
email me at:
macdan at comcast dot net
|
|
theory and explanation
I figured a way to cleanly peel the bezels off a
TiBook display and figured I'd share my technique.
If you've ever done this you'll know how difficult
it can be to remove the bezel parts from the LCD
without bending the heck out of the metal,
especially the front bezel. I did a couple using
the pull and peel method and the results weren't
pretty.
On a broken-LCD-acquisition I used a piece of
thin stiff plastic which I slid around the edges.
It popped off the bezels cleanly with virtually no
damage.
While it may be possible to open a bezel just
part way, I think it's best to completely remove
the bezels. Opening just one corner or side bends
parts which of course results in . . . well, bent
parts. :-\ By loosening the adhesive one can pop
the entire thing loose without the need to pry or
bend.
That's where the plastic strip technique comes in
handy.
The plastic I used came from some sort of
blister-packed product. The plastic was marked
PETE, which must be some flavor of
polyethelyne-whatever. In any case, it's very dense
and stiff, but thin enough to be pretty
flexible.
I cut up the plastic into a strip maybe 2" wide
x several inches long. This is your Thin Strip
o'Plastic Tool or TSPT. It's stiff
enough to be slid along under the bezel but not so
thick it bends up the metal.
I've since taken apart several more displays
using the same method with excellent results.
|
|
the takeapart
Getting the strip started into the display edge
was the toughest part. Once I could get the strip
there everything went pretty smoothly. It's good to
have extra plastic as well as some scissors handy
with which to trim as the corners of the plastic
strip get buggered up pretty quick.
I had to do some prying to spread the corner by
the hinge which allowed me to slip the strip in.
Here's pics sliding the strip along under the
bezel.
I find that if I get stuck on one section I can
usually get another part going until I have gotten
most all of it unstuck. At that point, the whole
thing seems to just kind of pop apart in my
hands.
The key for me has been to not force anything.
If I find I cannot get any further in one place, I
move on until I find a place I can do something. It
really takes a bit of patience and persistance to
get that fragile bezel face off without buggering
it up badly. I buggered up a couple before I got
the hang of it. :-)
Just a note here to report a warning from one
reader . . . the LCD has a metal frame around it
just under the external bezel. It is possible to
accidentally get your plastic strip tool under that
and damage the LCD itself. Just be aware that you
want to remove only the outer painted bezel, not
the underlying LCD frame.
|
About the display
and its construction
The working strength of the display comes from
its gluedup construction. It's assembled with some
very strong tough adhesives which turn the
individual parts into a very strong assembly, a
monocoque. If any of the parts of the glued up
system are missing the structural integrity of the
whole is compromised.
The bezel back is a formed shallow titanium pan,
painted on the outside. There are titanium tabs or
flanges welded to the side and top edges. The welds
holding the tabs to the back are fragile, so be
careful not to damage them opening the display. The
LCD is screwed to the bezel back through holes in
the tabs.
The bezel face is made of aluminum (I believe),
painted to match. It's very thin and easily bent,
and once distorted very difficult to straighten
back to its original appearance. It is attached to
the display assembly entirely with adhesive.
The hinges are of a cast pot metal and somewhat
brittle. Their longterm strength comes from being
fastened into the bezel back with a structural
adhesive.
There are thin shims near each side screw which
fill a slight gap. If missing the tightened side
screws can easily crush the hinge sides, the
spacers and/or the back bezel inner tabs.
Here's a crossection of the assembled
display.
|
Glue
There are three types of glue used in the
display.
- a thin bead of dark gray very dense and
tough epoxy-like stuff (actually a 2-part
acrylic adhesive) goes around the entire inside
ot the back bezel. It holds the hinges, the
center 'tube' and the spacers in the upper sides
and top. (Green in
the image above.)
- a clear, rubbery glue, almost certainly
hot-melt, is used to (temporarily, most likely)
locate the LCD into the bezel back assembly
(Pink above)
- a thin layer of a brownish, very hard, but
somewhat brittle glue fastens the bezel front to
the LCD edges and spacers and hinges.
(Orange above)
Here's some additional info, gleaned from Apple's
patent application. The adhesive discussed below
used to assemble the main body does appear to be
the same as that used to attach the hinges and
spacers, as described above.
I've wondered what sort of adhesive Apple used in
the TiBooks. I stumbled across some relevant info
in one of Apple's patents,
"patent number 6,574,096 - Use of titanium in a
notebook computer". (Here's a search
that calls up all of Apple's patents, an
interesting adventure in its own right.)
Patent number 6,574,096 has lots of details on
the TiBook's design and construction, plus it has
interesting 'discussions' about Ti glue - go down
about 2/3 of this page (or just repeatedly search
the page for 'glue'.)
From the above page:
- "Virtually any type of glue suitable for
bonding injection molded materials to titanium
or titanium alloys may be used. An exemplary
glue suitable for use in various embodiments of
the present invention is Lord's glue 201/19
manufactured by the Lord Corporation of Cary,
N.C."
Here's on Lord Corporation's web site is their
"Engineered
Adhesives" page. I had a heck of a time finding
just what sort of glue is '201/19', but eventually
found infos in this doc.
ACRYLIC ADHESIVES - LORD 201/19
- Applications - Bare metals, plastics and
composites
- Working Time - 5-8 minutes
- Handling Time - Fast, 12-16 minutes
- Full Strength - 2 hours, heat cure typically
not recommended
- Easy to dispense, Self-leveling
- Comments - Minimal surface preparation, fast
cure, good environmental resistance.
Now I just need to follow up and find a source
from whom I can actually purchase some of this
stuff . . .
Permatex makes something which appears to be a
similar product called PermaPoxy 5 minute Plastic
Weld. Recently I bought a tube in a local auto
parts store. It does stick very nicely to metals
and plastics, but it's best used in a well
ventilated area as the fumes are ferocious!
|
Putting it back
together
The hinges, surrounding spacer and central lower
'tube' are glued into place using 2-part acrylic
adhesive. You'll want to pry out the remains of the
old hinge(s) as well as old glue along the area
where the replacement hinge is going to lie. Use a
solvent of some sort (like alcohol or paint
thinner) to make sure the area is free from oils
and dirt before glue-up.
Keep in mind the hinges are 'handed', not
interchangable between sides, so make sure you've
got the proper side in hand before mixing and
applying adhesive.
Run a bead of adhesive along the edge of the
hinge and press the hinge into place inside the
bezel back. Use clamps to hold the hinge in place
while the adhesive cures, spring-loaded clothespins
work well.
Before proceding any further, ensure the center
tube is solidly glued, if not use some more of the
same acrylic adhesive to stick it back in place,
clamp and let cure.
I'd let the glue cure overnight at least, just
to be sure it's holding well. IN fact, I'd do a bit
of tugging and prying at the well-cured glued parts
just to be sure they are solidly attached. If you
can easily pull up your newly attached hinge, you'd
better try again before finishing up the job,
eh?
If you don't need disturb the hinges or other
bits surrounding the LCD inside its bezel, it's a
pretty straight forward job. The LCD isn't really
glued to the bezel back at all, just a couple of
dabs of hotmelt and the four screws on the
sides.
Once the LCD is installed into the bezel rear,
some (masking) tape around on the very edge of the
LCD screen face will keep squeeze-out off the
screen. In fact, it's probably a good idea to mask
all nearby external painted surfaces.
The bezel face can be reattached using an
adhesive suitable for glueing metal to metal. I'd
not use epoxy. I don't know what Apple used,
but the original stuff is thin, brown, hard and
brittle. For starters, I'd suggest common household
cement. Here in the states Duco is a widely
available name brand, but anything similar ought to
work.
You might want to test-practice with the old
broken LCD before the final assembly to determine
the appropriate amount of glue to use. It always
enhances one's confidence level when you've
practiced first. :-D
Run a thin bead of glue around the LCD frame's
face, being careful to keep the glue more to the
LCD's outer edge than the inner (you want minimize
squeeze-out onto the LCD screen.) Position the
bezel face on the LCD and using lots of
clips (springloaded clothespins are perfect) clamp
all around. Might be a good idea to wipe off any
squeeze-out before it dries, though if
you've masked well it shouldn't be necessary.
In situ or take apart?
If the LCD data cable is intact it's possible
to do the job without dismantling the 'Book to
remove the cable from the unit's base, do the LCD
replacement with the bezel back and hinges still in
place. Removing the data cable from its internal
connector does require nearly complete disassembly
of the 'Book.
The internal backlight connector has to
disconnected of course, and on the pre-DVI 'Books
is a PITA to get at, but it is possible.
With the keyboard out you can feed in the new LCD's
backlight cable through the hinge opening and guide
into its socket from the KB side. I found a thin
very long-nosed ex-medical tweezer very useful
feeding the cable through the hinge opening. See
below for more details.
Still, it's not terribly difficult to remove
the entire display and that method is to be
preferred as it allows you to work on the display
unencombered by the PowerBook's body. The ifixit
web site's takeapart guides are quite good.
Completely removing the entire display, I can
replace a complete display assembly in roughly 1 hr
total, but I expect a first-timer might take
several, even with a manual onhand. Even if one
fixes the existing broken display, it still makes a
lot of sense to remove the complete panel, makes
things alot easier to manage. The data cable is
very vulnerable to damage, so be super careful
whenever you have to fiddle with it.
|
LCDs and cables
The LCDs
All the LCDs are of the same form, with the same
connectors and screw-hole locations. Any LCD will
fit into any of the bezels.
Here's some LCD part numbers of which I'm
aware:
400/500/550/667 pre-DVI models - 1152x768
- Samsung PNs LTN152W1-L01, LTN152W2-L01
- AU Optics Corporation - PN B152W01
- LG/Philips PN LP152W1
667/800/867/1gHz DVI models - 1280x854
- Samsung PN LTN152W3-L01, LTN152W4-L01,
LTN152W5-L01 (?)
- AU Optronics Corp B152EW01
The earlier LCDs work fine on the DVI models,
but at the lower rez of course. Interestingly, a
DVI LCD worked on my 400mhz test unit, but it
displayed only the lower rez output to the upper
left of the screen. It had 128 pixels of odd
static-like artifacts at the right edge and
repeated pixels from the top at the bottom
edge.
Some potential non-Apple LCD sources:
- VPR Matrix 110 Laptops......15.2" Wide
Screen. B152EW01
- VPR Matrix 220A5 Laptops
- VPR Matrix 200A5 Laptops
- VPR Matrix 185A5 Laptops
- Gateway M500 Laptops
The cables
There are three cables from the display assembly
to the main section of the 'Book. On the lefthand
side are the LVDS cable (the main data cable) and
the sleep LED cable. On the righthand side is the
backlight cable.
The LVDS cable is a multiple wire jobbie (20
wires?) and is the largest and most fragile of the
three cables.
The sleep LED cable is usually blue and white.
The backlight cable is usually pink and white,
though I have seen LCDs with BL cables in other
colors, including blue, and gray.
The backlight cable is part of the LCD, it plugs
into the invertor in the main body, either directly
or via an 'extension cable', depending on which
model TiBook you have. It is not removable
from the LCD.
- The display LVDS data cable
The LVDS cable is separate from the LCD, one end
plugs into the back of the LCD and the other into
the logic board just inside and below the left
hinge. The LVDS connector location on the 'Books'
logic boards remains the same over all TiBook
models.
There are several different LVDS cables and
while all appear functionally identical, practice
reveals differences. I did some testing with a DVI
TiBook and some pre-DVI LCDs, and the difference
seemed to be in the cable, some cables able to
communicate the correct rez and others not. Here's
the two possible results:
A) System sees an 1152x768 LCD and displays that
rez properly
. or
B) System imagines a 1280x854 LCD, which doesn't
all fit on the real 1152x768 LCD and thus the extra
pixels are 'offscreen' and not visible.
LVDS cables on a DVI 667, with pre-DVI
LCDs
- -LG/Phillips LP152W1
- -Samsung LTN152W1 and LTN152W2
cable
PN#...............LCD..............output
------------------------------------------------------
590-5081 rev A.......LP152W1........1280x
590-5081 rev A.......LTN152W2......1280x
590-5156 rev A*.......LTN152W1.....1280x
- *Foxxconn - blue and gold wires, w/green
tape
590-5156.rev.B.......LP152W2.........1152x
590-5156 rev B*.......LTN152W1......1152x
- *blue wires
590-5156-01*..........LTN152W1......1152x
- *green wires
Sadly, I didn't keep track from which TiBook
each of the cables was sourced, as that would have
been rather useful to know. :-(
Disclaimer: Please note I won't
guarantee the above data to be valid on any machine
other than the one on which I did my
testing.
The LVDS cable is
composed of a bunch of tiny coax cables, each
roughly 0.3mm in diameter. Use extreme care
handling the cable as it is very easily damaged. If
it does get damaged, it's pretty much junk as it's
virtually impossible to repair.
|
|
The sleep LED cable has a plug at one end and
the sleep LED at the other. It plugs into the logic
board right next to the LVDS cable. The LED on the
other end is clipped into the center tube below the
display and is removeable, though unclipping it is
near enough impossible without removing the LCD
from the display housing. The sleep LED connector
location on the 'Books' logic boards remains the
same over all TiBook models.
Pre-DVI have their inverter boards in a
different place than do the DVI models, and so the
procedures for disconnecting and reconnecting the
BL cable vary. In both cases the inverter can be
plugged in without removing the LB, but each
requires a slightly different procedure. The BL
cable feeds through the hinge hole, then . . .
The inverter on the pre-DVI models is located
under at the right rear of the case, just to the
right and forward of the hinge hole. If you pull
the keyboard and/or take off the bottom you can
more readily see where it plugs in. If you look
through the hinge-hole you can just see the
plug in its socket. Use a small flashlight or
something to help see inside there. It's pretty
easy to pull the old one out, but a PITA to work
the new one in. Just take care to note the
orientation of the old BL's plug.
The plug is pointed to the right viewed from the
'Book's front. If you grab those wires and tug
gently to the left the plug will come out of its
socket. Be sure to note the orientation of the plug
as it comes out, it only fits into its socket one
way. That's the easy part. The PITA is getting the
replacement back in.
Here's my 'procedure' for plugging in the damn
thing:
First, with the re-assembled display attached to
the main body by the hinges but with the hinge
covers off, open the display 90 degrees and stand
the whole 'Book on its side. The right side if
you're right-handed (the left if you're a lefty?).
As I'm a righty I'll describe it from that POV.
I have a skinny long-nosed tweezer with which I
can work the plug through the hinge-hole (with my
right hand.) With my left hand I then use a
screwdriver or similar to guide the plug, through
the KB opening, directing the plug downwards (to
the 'Book's right.) Using the tweezer from the back
through the hinge-hole and a screw driver through
the KB opening I am able to orient the plug and
push it into place.
I have to say, this is even more difficult (for
me anyway!) than it sounds, it's the single biggest
PITA of the entire LCD replacement job. However as
it's an even bigger PITA to strip the entire 'Book,
I suffer on through til I get the damn thing into
place.
The DVI TiBooks are easier, the inverter is
located up by the optical drive with an 'extension
cord' running back to the LCD's BL plug. To access
the connection, remove the power-in board and the
fan (though IIRC a 667-DVI doesn't have a fan
there, just an empty bracket.) You can then get at
the BL plug's connection to the 'extension
cord'.
Hinges
Original hinges are made of some sort of pot
metal, the most recent new replacement units are
apparently made of steel. It is possible to reuse
old hinges as long as they are intact without any
cracks.
Sleep magnets
A tiny cylindric magnet taped to the back of the
LCD trips a sensor under the palmrest.
Looking at the back of the LCD with the top edge
up, the magnet location relative to the upper LH
corner:
- 400 and 500 - right 4 3/4" and down 1
1/4"
- . . . . r-121mm and d-31mm
- 550 and later - right 7 3/4" and down 2
3/4"
- . . . . r-197mm and d-70mm
Those positions of course can also be located on
the palmrest ('Book open and facing you) measured
from the near righthand corner, left and toward the
back. You can trigger sleep with the lid open by
placing a magnet there. Heck if you didn't
have an exact location you could just slide a
magnet around the palmrest until the 'Book nods
off.
LCD failure modes
There are a number of obvious failure modes
about which folks complain, here's some of the more
common problems and their likely causes:
- partial blanking of the LCD (eg: lower
third of screen)
Probably a bad cable, generally caused by
physical damage. However, edge separation of the
LCD from its integrated controller board's cabling
can also cause this problem. First case requires
cable replacement, second requires LCD
replacement.
- all-white screen, external display still
works
Maybe controller failure on the LCD itself, but
more likely failed output circuit on the logic
board. See my page on the subject here.
Almost certainly failure of contacts at the edge
of the LCD itself. Replace LCD.
- dark screen, image faintly
visible
Failed backlight - either the backlight's power
source (invertor) or a failed TTFL bulb in the LCD
itself. It's also possible the wiring from the
inverter to the LCD have been severed or grounded.
Last case can destroy inverter, check wires before
replacing inverter.
Old backlight bulbs give off less light as they
age. Generally the cure is to replace the LCD, but
it is possible to replace just the bulb itself
though the job is not for the faint of heart.
- moving display causes display
issues
Usually caused by failing LVDS cable, though LCD
edge connection failure can also be the cause.
While keeping the entire assembly still, try
squeezing the edges of the display gently to see if
you can stimulate the problem. If merely squeezing
the edge causes it, it's almost certainly an LCD
problem.
Some info about LCD edge
connections
The built-in controller on these LCDs connects
to the actual LCD panel at its edges via flexible
ribbon cable adhered with anisotropic conductive
film, or ACF for short. The following quote comes
from http://www.microbonding.com/gb/hs_gb.htm
Anisotropic conductive film, commonly
known as ACF, is a epoxy system that has been
used for almost 30 years in the flat panel
display industry to make the electrical and
mechanical connections from the drive
electronics to the glass substrates of the
displays. Since 10 years, this technology is
largely employed to directly connect the drivers
on glasses; this process is called Chip On Glass
(COG).
ACF works by trapping conductive particles
between the corresponding conductive pads on a
substrates and the piece to be connected (die,
LCD, other substrates,...). ACF consists of a
very stable matrix of 3-5µ polymer spheres,
each nickel-gold plated and then coated with a
final insulating layer that protects them
against shorting through contact with a
neighboring particle.
During the bonding process, the insulation in
the Z-axis where the balls are trapped is pushed
away, allowing the Ni-Au layer on the particle
to conduct electricity between the IC and the
substrate, while not shorting in the X and Y
directions. The epoxy cures, locking the
particles in this compressed state. The resin
matrix used by ACF is either thermopastic or
thermoset, thus bonding is done through
simultaneous application of heat and pressure
with a thermode.
It is possible to replace failed ACF adhesive
film with new, but the technique requires some
specialized tooling to ensure the bond is properly
complete. There are several outfits that can do the
job, but generally cost is higher than simply
replacing the LCD.
|
back to macdan
revhist
2007.04.27 - reorg and added some details (hinge
assembly, LVDS cable diffs, sleep magnet locations, LCD
failure modes, LCDs and ACF)
2005.01.18 - added LVDS cable crossection image
2004.08.26 - updated LCD and cable details, added some
more take-apart
2004.04.26 - new page
|